1. Field of the Invention
The present invention relates to an indicator system of reduced size, weight and low power consumption for hand-held field applications. In particular, the present invention relates to an alarm system which is capable of being interfaced with portable chemical monitors. Most particularly, the present invention is an alarm system for the Chemical Agent Monitor (CAM) and Improved Chemical Agent Monitor (ICAM).
2. Brief Description of the Related Art
Today's military forces are confronted with the possibility of encountering chemical agents in battlefields. Monitoring for possible chemical contamination aids in countering the threat residual chemicals pose to exposed individuals. Constant identification of chemicals in an environment aids in the appropriate protective measures and treatment of chemical exposure.
Monitors have been used in military and civilian operations to test air quality within an area for possible chemical contamination. These monitors allow environmental sampling throughout an area of military operations or civilian use. Generally, the monitors are either mobile monitors which may be carried by individual soldiers, or area monitors placed at fixed points within an area.
Militarily, mobile monitors are important because they allow rapid monitoring of the immediate area close to soldiers, either from current or residual effects. They may be hand-held, and of various weights. This localized detection allows soldiers to react immediately to the positive detection of chemical agents. Reduced reaction time minimizes chemical exposure to soldiers within an operational area. Early detection significantly increases the chances of survival of the soldiers and the successful completion of the mission.
Several types of toxic chemical compounds are known. These include mustard and nerve agents. Mustard agents or gases, also called blister agents, may be nitrogen or chlorinated sulfur compounds. The most common type of mustard agent are the chlorinated sulfur compounds. Long after mustard gas was discovered in 1822, it was used in World War I as a chemical warfare agent, causing approximately 400,000 casualties. The sulphur mustard gas is chemically known as bis-(chloroethyl)-sulphide. The nitrogen mustard gas is chemically known as tris(2-chloroethyl)amine. Mustard gas is a colorless, oily liquid having a garlic or horseradish odor. It is slightly soluble in water, complicating removal by washing. It primarily attacks humans through inhalation and dermal contact, having an Airborne Exposure Limit (AEL) of 0.003 mg/m.sup.3. Mustard gas is a vesicant and an alkylating agent which produces a cytotoxic reaction to the hematopoietic tissues. Symptoms usually begin to take effect 4 to 24 hours after initial contact. The rate of detoxification of mustard gas is slow and repeated exposure yields a cumulative effect.
Nerve agents or gases were discovered in 1936, during research on more effective pesticides. Nerve agents inhibit certain enzymes within the human body from destroying a substance called acetylcholine. This produces a nerve signal within the body forcing the muscles to contract. Nerve agents have an Airborne Exposure Limit (AEL) of 0.00001 mg/m.sup.3.
Types of chemical monitors include the Chemical Agent Monitor (CAM) developed by Grasby Ionics, Inc. of Watford Herts, England, and the Improved Chemical Agent Monitor (ICAM) developed by Grasby Ionics, Inc. of Watford Herts, England, Environmental Technologies Group of Baltimore, Md. and the United States Army at Aberdeen Proving Grounds of Aberdeen, Md. The CAM or ICAM, referred to as CAM/ICAM, is carried by individual soldiers in the field and provides for detection of nerve and blister chemical agents.
There has been a long-standing need for alarm systems which are increasingly small but retain the capabilities and performance of larger-size monitors. Over the years, attempts have been made to decreased size, weight, power consumption, maintenance of the monitors, while increasing monitor speed and ease of use. Monitors should also permit the quick attachment and detachment of individual monitor parts while permitting the operators to maintain protective measures/gear integrity. Hand-held monitors become problematic with decreased sizes that are difficult to handle with protective clothing being worn.
In view of the foregoing, improvements in chemical monitoring have been desired. It has been desired to provide reduced size, weight and power requirements, while improving the durability of the monitors and the ease of field manipulations. The present invention addresses these needs.